Reciprocating engine,pump or motor



Nov. 11, 1969 D. E. JOHNSON 3,477,345

RECIPROOATING ENGINE, PUMP OR MOTOR Filed Aug. 25, 196'? I 2 Sheets-Sheet l INVEN TOR DON auouwsou 35 FiG.2 v BY ;;(Q@

ATTORNEYS 1969 D. E. JOHNSON 3,477,345

RECIPROCATING ENGINE, PUMP OR MOTOR 2 Sheets-Sheet 2 Filed Aug. 25, 1967 m T N E V W DON E. JOHNSON ATTORNEYS- United States Patent O US. Cl. 91207 11 Claims ABSTRACT OF THE DISCLOSURE A first closed-ended cylinder receives a piston that is fixed on a rotatable shaft. A means extends outwardly from the first cylinder to engage an undulant groove in an outer cylindrical housing. A second cylinder inside the housing circumscribes the first cylinder and is coupled to it, while the cylinder assembly is coupled to the shaft. Pressurized fluid enters the first cylinder on one side of the piston adjacent one end of the first cylinder, and enters the second cylinder exteriorly of the opposite end of the first cylinder. This provides pressure on both ends of the first cylinder that drives it axially through a stroke, which because of its engagement with the groove is caused to rotate, turning the shaft. A similar effect drives the first cylinder through the return stroke, and as the cycle is repeated the shaft is rotated continuously.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a device that will serve as an engine, fluid motor or pump.

Description of the prior art Engines, pumps and fluid motors commonly are made to include a piston that reciproc-ates in a cylinder, with translation between rectilinear movement and rotation being accomplished by a rod and crank connected to a shaft. The size and weight of such devices are relatively great for the amount of output obtained, and they are rendered somewhat complex by the necessity for the crank and associated items. Also, even a double-acting piston has a limited pressure area for contact with the fluid.

SUMMARY OF THE INVENTION The present invention includes an outer housing having at its axis a rotatable shaft. A piston is fixed on the shaft, so that it will turn with the shaft but not move relative to it. Circumscribing the piston is a cylinder that is somewhat longer than the piston and movable axially relative to the shaft and piston. A second and still longer cylinder circumscribes the first cylinder and is coupled to the shaft to rotate with the shaft. The first cylinder slides axially back and forth in the second cylinder to which it is coupled. The first cylinder includes a projection extending into a sinusoidal groove in the outer housing. Consequently, when the second cylinder is moved axially, it is caused to rotate by reason of the engagement with the sinusoidal groove. The first cylinder turns the second cylinder, which is coupled to the shaft and causes the shaft to rotate. Fluid to operate the device as an engine or motor is introduced between the piston and one end of the first cylinder, and between the opposite end of the first cylinder and the adjacent portion of the second cylinder. This provides two pressure areas for advancing the first cylinder through its stroke. It is returned by the pressurized fluid being applied oppositely so that, for movement in either direction, it receives pressurized fluid on two surfaces.

An object of this invention is to provide a lightweight, compact fluid energy device with a high output.

Another object of this invention is to provide a fluid energy device of small size, yet with a large net piston area.

A further object of this invention is to provide a fluid energy device of relatively simple construction providing also a neat, uncluttered exterior appearance.

An additional object of this invention is to provide an engine or motor in which the reciprocating member provides two pressure areas during its movement through its stroke in either direction.

These and other objects will become apparent from the following detailed description taken in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a top plan view, partially broken away, of the device of this invention, with the first cylinder at one end of its stroke;

FIGURE 2 is a longitudinal sectional view of the device, with the first cylinder at the opposite end of its stroke;

FIGURE 3 is a transverse sectional view taken along line 3--3 of FIGURE 1; and

FIGURE 4 is a perspective view of the device, partially broken away.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawing, the device of this invention is constructed as a steam engine. However, it is adaptable also for manufacture as an internal-combustion engine, as a fluid motor or as a pump.

The device includes an outer housing 9 of cylindrical configuration, having a hub portion 10 at one end and a bearing retainer 11 held by screws 12 at the other. Bearings 13 and 14 at the axis of the housing 9 rotatably mount a shaft 15. Mounted on the central portion of the shaft 15 is a piston 16 which is fixed relative to the shaft 15 so that it rotates with the shaft, but does not move axially.

Circumscribing the piston 16 is an inner cylinder 18 that is coaxial with the shaft 15. This cylinder includes a circumferential wall 19 and radial end walls 20 and 21 that are spaced apart and located on opposite sides of the piston 16. Piston rings 22 and 23 are included on the periphery of the piston 16 to provide a seal at the adjacent circumferential wall 19 of the inner cylinder 18.

A second and larger cylinder 25 is located within the housing 9 and around the inner cylinder 18. The cylinder 25 has radial ends 26 and 27 and a circumferential wall 28 that is adjacent the circumferential wall 19 of the inner cylinder 18. An annular slot 29 is included in the circumferential wall 28 of the outer cylinder 25, so that the cylinder 25 is split into two segments. Both parts of the cylinder 25 are connected to the shaft 15 so that the cylinder 25 and the shaft rotate together. The outer cylinder 25 includes piston rings 30 and 31 bearing against the wall 19 of the inner cylinder 18. Similarly, the inner cylinder includes piston rings 32 and 33 bearing against the inner surface of the wall 28 of the outer cylinder 25.

Projecting radially outwardly from the circumferential wall 19 of the inner cylinder 18 is an annular rib 34, which extends through the slot 29 in the circumferential wall 28 of the outer cylinder 25. A tubular flange 35 is carried by the outer edge of the rib 34 and extends around the exterior of the circumferential wall 28 of the outer cylinder 25.

As best seen in FIGURES 3 and 4, the outer surface of the wall 28 of the outer cylinder 25 is provided with a pair of opposed longitudinally extending grooves 37. The

flange 35 includes a pair of longitudinally extending ribs 38 which fit complementarily within the grooves 37. By this construction, therefore, the flange 35, and hence the inner cylinder 18, are permitted to move axially relative to the outer cylinder 25 as the ribs 38 slide in the grooves 37. However, the presence of the ribs 38 in the grooves 37 couples the inner and outer cylinders so that they rotate together.

A pair of diametrically opposed pins 39 projects radially outwardly from the flange 35. These pins fit within a sinusoidal groove 40 formed in a tubular liner 41 carried adjacent the outer circumferential wall of the housing 9. The engagement of the pins 39 with the groove 40 means that, upon movement of the inner cylinder 18 in an axial direction, it is compelled also to rotate as the pins 39 must follow the groove 40. This rotation of the cylinder 18 also turns the outer cylinder 25 because of the coupling between the ribs 38 in the slots 37. This, in turn, rotates the shaft 15 which is connected to the outer cylinder 25. Thus, the concentric cylinders 18 and 25 and the shaft 15 rotate as a unit, while the inner cylinder 18 also reciprocates.

The hub portion of the housing 9 includes a radial port 43 connecting through an annular recess 44 to a passageway 45 in the shaft 15. Radial openings 46 and 47 connect the exterior of the shaft inside the housing with the passageway 45. The opening 46 is within the inner cylinder 18, to the left of the piston 16 as the device is illustrated. The opening 47 is outside the inner cylinder 18 but within the outer cylinder 25, to the right of the radial wall 21 of the inner cylinder 18 as the device is shown in FIGURE 2.

An additional port 48 is provided in the hub portion 10, leading to a passageway 49 in the shaft 15. Openings 50 and 51 extend through the shaft to communicate with the passageway 49. The opening 50 is outside the inner cylinder 18 but within the outer cylinder 25, disposed to the left of the radial end wall of the inner cylinder as the device appears in FIGURE 2. The aperture 51 is within the inner cylinder, to the right of the piston 16 as the device is illustrated.

As the device is shown in FIGURE 2, the reciprocating inner cylinder 18 is illustrated at the left-hand end of its stroke. To reach this position, steam is admitted through the port 43 into the passageway 45. The steam leaves the passageway through the opening 46, where it is confined within the inner cylinder 18 between the left-hand radial end wall 20 and the piston 16. With the piston 16 being fixed relative to the shaft, the force of the steam within the cylinder 18 forces the cylinder 18 toward the left. Additional steam leaves the passageway 45 through the aperture 47, entering the outer cylinder 25 where it is confined between the radial end wall 27 of that cylinder and the end wall 21 of the inner cylinder 18. The steam in the cylinder 25 also exerts a force on the cylinder 18, urging the cylinder 18 to the left. Thus, both ends of the cylinder 18 receive impetus from steam. which enters the engine, and a large force is generated to shift the cylinder 18 toward the end of its stroke. As the piston moves in this manner, the openings and 51 and the apparatus 48 and 49 act as exhaust passageways.

After the cylinder 18 has reached the left-hand end of its stroke, as shown in FIGURE 2, the porting is reversed. In other words, the port 43 now is connected to exhaust, while steam enters the port 48 in the hub section 10. The steam from the port 48 enters the passageway 49, discharging through the openings 50 and 51 into the outer and inner cylinders, respectively. The steam discharging from the port 50 is confined between the left-hand end wall 26 of the outer cylinder 25 and the left end wall 20 of the inner cylinder 18. Consequently, this steam exerts a force urging the cylinder 18 back to the right-hand end of its stroke. Also, the steam from the port 51, being confined between the piston 16 and the wall 21, urges the cylinder 18 toward the right. Thus, when the porting is reversed, the direction of movement of the cylinder 18 also is reversed. As this reciprocation takes place, the pins 39, guided in the sinusoidal groove 40, cause the rotation of the inner cylinder 18 and, hence, the outer cylinder 25 and the shaft 15. Thus, the shaft is turned continuously as the cylinder moves back and forth.

The valve for controlling the connections between the ports 43 and 48 and the steam supply and exhaust may be conventional and of the type commonly used for doubleacting steam engines. An example of such a valve is found on pages 1215 and 1216 of Mechanical Engineers Handbook, Fourth Edition, edited by Lionel S. Marks, McGraw-Hill Book Company, Inc.

The arrangement of such a valve also is shown in the upper right-hand portion of FIGURE 2. It includes a chamber 52 connected by line 53 to a steam generator 54. Lines 55 and 56 connect to the chamber 52 at spaced locations and extend to the ports 43 and 44, respectively. An exhaust is provided by the port 57 intermediate the lines 55 and 56. Within the chamber 52 is a slide valve 58 connected to a rod 59 that extends exteriorly of the chamber 52 and pivotally joins a link 60. The latter member pivotally connects to an arm 61 driven by a shaft 62 which is rotated by the shaft 15 of the engine, as indicated by the dashed line in FIGURE 2. Rotation of the shaft 62 and the arm 61, acting through link 60, causes reciprocation of the rod 59 which, in turn, causes reciprocation of the slide valve 58. This, alternately, connects the lines 55 and 56 to the steam. inlet, while the line not so connected communicates with the exhaust 57. The valve depicted in FIGURE 2 is merely illustrative of many valves, including rotary valves, which can be used with the engine of this invention.

The engine is very light and compact in size, yet generates substantial power because of the application of the steam pressure to the two surfaces during movement in either direction. The engine is made even more compact through the use of the sinusoidal groove in the outer cylinder, eliminating the need for a separate crank and rod assembly. The use of concentric parts, including the cylindrical outer housing, results in a neat outer appearance, as well as reducing the size of the engine.

I claim:

1. A fluid energy device comprising:

an axially fixed piston member,

a reciprocative means,

said reciprocative means having a duality of walls for engagement with fluid,

one of said walls being located on one side of said piston member, the other of said walls being located on the opposite side of said piston member,

a cylinder circumscribing said reciprocative means,

guide means for causing said reciprocative means to rotate upon reciprocation thereof,

a shaft coupled to said reciprocative means for rotation therewith, and

means for introducing fluid between one side of said piston member and one side of one of said walls of said reciprocative means and simultaneously introducing fluid into said cylinder adjacent the opposite side of the other of said walls of said reciprocative means for moving said reciprocative means through a stroke in one direction, and alternately for introducing fluid between said piston member and the other side of said other wall of said reciprocative means simultaneously into said cylinder adjacent the opposite side of said one wall of said reciprocative means for moving said reciprocative means through a stroke in the opposite direction.

2. A device as recited in claim 1 in which said means for causing said reciprocative means to rotate includes means defining an undulant path, said reciprocative means including means extending to said undulant path for being guided thereby.

3. A fluid energy device comprising:

a rotatable shaft,

a piston means fixed on said shaft,

a first cylinder circumscribing said shaft and said piston means,

said first cylinder being reciprocative axially of said shaft, and having an end wall on either side of said piston means, a second cylinder circumscribing said first cylinder,

said second cylinder being axially fixed relative to said shaft, and having a greater length than said first cylinder, means for causing said first cylinder to rotate upon reciprocation of said first cylinder axially of said shaft, means for introducing fluid into said first cylinder between said piston means and one of said end walls of said first cylinder and admitting fluid into said second cylinder exteriorly of the other of said end walls of said first cylinder, and alternately for admitting fluid into said first cylinder between said piston means and said other of said end Walls of said first cylinder and into said second cylinder exteriorly of said one end wall of said first cylinder, and

means coupling said first cylinder to said shaft.

4. A device as recited in claim 3 in which said mean-s for causing said first cylinder to rotate comprises means defining an undulant path exteriorly of said first cylinder, said first cylinder including means extending to said path for being guided thereby.

5. A device as recited in claim 3 in which said means for causing said first cylinder to rotate comprises means defining an undulant groove extending around said first cylinder exteriorly thereof, said first cylinder having pin means extending into said groove for being guided thereby.

6. A device as recited in claim 3 in which said means for causing said first cylinder to rotate comprises means defining a sinusoidal groove extending around said second cylinder exteriorly thereof, said first cylinder having pin means projecting outwardly therefrom and into said groove, said second cylinder having a slot therein for allowing said pin means to extend therethrough to said groove.

7. An engine comprising:

a shaft,

means for mounting said shaft for rotation about the axis thereof,

a piston on said shaft,

said piston being coupled to said shaft and axially fixed relative thereto,

a first cylinder circumscribing said piston and said shaft,

said cylinder having a circumferential wall and opposed radial end walls extending from said circumferential wall to said shaft,

said opposed radial end walls being on opposed sides of said piston,

21 second cylinder circumscribing said first cylinder,

said second cylinder having a circumferential wall,

and

opposed radial end walls,

said second cylinder being longer than said first cylinder,

said second cylinder having a slot in said circumferential wall thereof,

said first cylinder having means projecting outwardly through said slot,

guide means exteriorly of said second cylinder engaging said projecting means for causing said first cylinder to rotate upon reciprocation of said first cylinder,

means coupling said second cylinder to said first cylinder,

means coupling said second cylinder to said shaft,

means for introducing pressurized fluid in said first cylinder on one side of said piston adjacent one of said radial end walls of said first cylinder, and simultaneously introducing pressurized fluid into said second cylinder exteriorly of the other of said radial end walls of said first cylinder for moving said first cylinder through a stroke relative to said shaft, piston and second cylinder in one direction, and

means for introducing pressurized fluid into said first cylinder on the opposite side of said piston adjacent said other radial end wall of said first cylinder, and simultaneously introducing pressurized fluid into said second cylinder exteriorly of said one radial end wall of said first cylinder for moving said first cylinder through a return stroke in the opposite direction.

8. A device as recited in claim 7 in which said guide means includes:

means defining a sinusoidal path circumscribing said second cylinder,

said projecting means of said first cylinder being guided in said sinusoidal path for thereby causing said reciprocation of said first cylinder upon said reciprocation of said first cylinder. 9. A device as recited in claim 7 in which: said outwardly projecting means of said first cylinder includes flange means circumscribing said second cylinder adjacent said circumferential wall of said second cylinder, and

intwhich for said means for coupling said second cylinder to said first cylinder said flange means and circumferential wall of said second cylinder include a longitudinally extending groove in one and a longitudinally extending rib on the other extending into said groove, whereby said flange mean-s causes said first cylinder to rotate together with said second cylinder while relative axial movement thereof is permitted. 10. A device as recited in claim 7 in which: said guide means includes a circumferential element circumscribing said second cylinder,

said circumferential element having a sinusoidal groove therein circumscribing said second cylinder,

said projecting means of said first cylinder extending into said groove for being guided thereby to impart rotational movement to said first cylinder upon reciprocation of said first cylinder.

11. A device as recited in claim 7 in which both of said means for introducing pressurized fluid into said first cylinder include passage means extending through said shaft into said first cylinder.

References Cited UNITED STATES PATENTS 665,970 1/1901 Obuch. 749,864 1/ 1904 James. 1,289,795 12/ 1918 Johnson 91207 2,805,447 9/ 1957 Voges 91209 FOREIGN PATENTS 455,964 3/ 1950 Italy.

PAUL E. MASLOUSKY, Primary Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,477,345 November 11, 1969 Don E. Johnson It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 18, "44" should read 48 Column 6, line 25, "reciprocation" should read rotation Signed and sealed this 7th day of April 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E; SCHUYLER, JR. 

